Field of the Invention
The present invention relates to a cargo cart, and more particularly to a three-wheeled cart with a lifting drawbar.
Prior Art
The prior art includes various devices adapted to carrying coolers.
U.S. Pat. No. 4,873,841 to William Bradshaw for a portable cooler describes a two wheel device where the wheels are an integral part of the cooler. The wheels extend beyond the width of the cooler. In one embodiment of the current invention, maneuverability is improved by providing adjustable rear wheels so they are always positioned within the silhouette of the cargo. The drawbar design, of the current invention, also improves maneuverability when the unit is pushed backward through confined spaces.
U.S. Pat. No. 5,169,164 to Michael A Bradford Cooler Tote cart does not have a front support leg thus when the operator releases the handle the front of the cooler drops to the ground. The cooler must then be unstrapped and removed from the wheels prior to removing goods from within. In one embodiment of the current invention, the cargo need not be strapped to the card thus the cargo always remains horizontal and can be accessed without the cooler being removed from the cart.
U.S. Pat. No. 5,249,823 to Stephen T. McCoy and Jack G. Clark Jr. describes a size variable cart which is adjustable in length and width using five separate mechanical functions. In one embodiment of the current invention, length and width adjustment requires using only one mechanical function. The loosening of one hand nut releases both length and width, thereby allowing both features to be adjusted simultaneously. Retightening said hand nut securely locks both the length and width in place. The '823 device unit does not provide a rear cargo stop and it requires straps to contain the cargo. In one embodiment of the current invention, vertical posts are provided in both the length and width directions to secure the cargo without straps. The '823 device provides wheel arrangement similar to a four wheeled wagon. In one embodiment of the current invention, a single retractable centrally located front wheel or caster is attached to a drawbar so that the front wheel engages the ground as the drawbar is elevated releasing the cart's anchor leg. When the drawbar is released the cart front leg automatically contacts the ground, thereby anchoring the vehicle.
Most of the prior art for providing wheeled transport for coolers have wheels that are permanently attached to the cooler, or the cooler must be specifically constructed to be attached to the wheeling device. The devices for providing wheeled portability to luggage do not address the problem of maintaining horizontal stability so as to prevent the cooler from slipping off the cart and/or spilling the contents. These deficiencies are especially severe in view of the existing large number of heavy coolers made without wheeled transport means.